Macro Expansion in Tabular Environment

Question

I have many tab separated csv files which I would like to convert into tables automatically in tabular environment of latex. Tables are named: log_% where % can be one of the symbols \in {at,be,fr,....}. For example each file looks like below:

 
accuracy    timepred    timelearn   timelearn2  timelearn4  rmsetrain
0.987747    0.532   2.44    nan nan 0.987676
0.987747    0.528   2.396   nan nan 0.987676
0.987747    0.544   2.408   nan nan 0.987676
0.987747    0.496   2.388   nan nan 0.987676
0.987747    0.436   2.432   nan nan 0.987676
0.987747    0.428   2.444   nan nan 0.987676
0.987747    0.464   2.452   nan nan 0.987676
0.987747    0.428   2.452   nan nan 0.987676
0.987747    0.464   2.46    nan nan 0.987676
0.987747    0.484   2.448   nan nan 0.987676

I tried the below code which unfortunately does not work!

\documentclass{article}
\usepackage{xparse}% http://ctan.org/pkg/xparse
\usepackage{csvsimple}
\usepackage{etoolbox}% http://ctan.org/pkg/etoolbox
\usepackage{array}
\usepackage{pgfplotstable}
\newcounter{listtotal}\newcounter{listcntr}%
\NewDocumentCommand{\names}{o}{%
  \setcounter{listtotal}{0}\setcounter{listcntr}{-1}%
  \renewcommand*{\do}[1]{\stepcounter{listtotal}}%
  \expandafter\docsvlist\expandafter{\namesarray}%
  \IfNoValueTF{#1}
    {\namesarray}% \names
    {% \names[]
     \renewcommand*{\do}[1]{\stepcounter{listcntr}\ifnum\value{listcntr}=#1\relax##1\fi}%
     \expandafter\docsvlist\expandafter{\namesarray}}%
}


\begin{document}
\newcommand{\namesarray}{at,br,cz,dk,fi,ie,nb,no,pt,se,be,ch,de,es,fr,it,nl,pl,ru,uk}%
\foreach \i in {0,...,20}{
\newcommand{\name}{\names[\i]}
\name
\csvautotabular[separator=tab]{logs/log_\names[\i]} \par
}
\end{document}

By executing above code I get an error:

! Package csvsimple Error: File 'logs/log_\names [0]' not existent, not readable, or empty!.

The same example works by hard coding the symbol as follows:

\csvautotabular[separator=tab]{logs/log_at} \par

in place of

\csvautotabular[separator=tab]{logs/log_\names[\i]} \par

I uploaded the working solution by hardcoding on the following link: goo.gl/nbI5TQ
I believe the problem is that macro \i gets expanded and tabular environment fails to expand \names. But I am not sure. Is it possible to expand the macro \names[\i] as a group and not just \i?
I would appreciate any kind of minimal help to solve my problem.

Thanks :)

Answer 1

The code seems overly complex. If you just want to loop over the list of files, I think you just need a loop from etoolbox, say, and the relevant command from csvsimple.

For example with logs/log_at:

accuracy        timepred        timelearn       timelearn2      timelearn4      rmsetrain                                                           
0.987747        0.532   2.44    nan     nan     0.987676                                                                                            
0.987747        0.528   2.396   nan     nan     0.987676                                                                                            
0.987747        0.544   2.408   nan     nan     0.987676                                                                                            
0.987747        0.496   2.388   nan     nan     0.987676                                                                                            
0.987747        0.436   2.432   nan     nan     0.987676                                                                                            
0.987747        0.428   2.444   nan     nan     0.987676                                                                                            
0.987747        0.464   2.452   nan     nan     0.987676                                                                                            
0.987747        0.428   2.452   nan     nan     0.987676                                                                                            
0.987747        0.464   2.46    nan     nan     0.987676                                                                                            
0.987747        0.484   2.448   nan     nan     0.987676                                                                          

and logs/log_br:

accuracy        timepred        timelearn       timelearn2      timelearn4      rmsetrain                                                           
0.987747        0.532   2.44    nan     nan     0.987676                                                                                            
0.987747        0.528   2.396   nan     nan     0.987676                                                                                            
0.987747        0.544   2.408   nan     nan     0.987676                                                                                            
0.987747        0.496   2.388   nan     nan     0.987676                                                                                            
0.987747        0.436   2.432   nan     nan     0.987676                                                                                            
0.987747        0.428   2.444   nan     nan     0.987676                                                                                            
0.987747        0.464   2.452   nan     nan     0.987676                                                                                            
0.987747        0.428   2.452   nan     nan     0.987676
0.987747        0.464   2.46    nan     nan     0.987676
0.987747        0.484   2.448   nan     nan     0.987676

The .tex code

\documentclass{article}
\usepackage{csvsimple}
\usepackage{etoolbox}
\providecommand*\do{}
\begin{document}
\renewcommand*\do[1]{%
  #1
  \csvautotabular[separator=tab]{logs/log_#1}\par
}
\docsvlist{at,br}%,cz,dk,fi,ie,nb,no,pt,se,be,ch,de,es,fr,it,nl,pl,ru,uk}%
\end{document}

produces the following output

Note that this code assumes files are called logs/log_<xx>.tex or that the files are logs/log_<xx>. If they have a different extension, you need to specify it.

Answer 2

Be aware that

1. \csvautotabular[separator=tab] means that you need to use tabs instead of spaces for separating items within a line of the csv file.

2. the way in which TeX does process filenames is not the same on all platforms.
   E.g., when using MiKTeX 2.9 under Windows 7, TeX always assumes the filename-extension ".tex" if no filename-extension is provided. If the filename in question does not have an extension at all, you need to provide the dot (with no extension) anyway.
   E.g. if you wish to specify the file "log_at" in the current directory's sub-directory "logs", you need to write ./logs/log_at. . (If you specify ./logs/log_at (without trailing dot), (MiK)TeX will seek for the file "log_at.tex" in the current directory's sub-directory "logs".